<template>
  <div class="tag-wall">
    <div class="tag-cloud" ref="wrapper">
      <a v-for="(item, index) in data"
         :key="index"
         ref="tag"
         :href="'/articleSortList/'+item.id"
         slot="actions"
      >
        {{ item.name }}
      </a>
    </div>
  </div>
</template>

<script>
export default {
  name: 'ArticleLableSub',
  data() {
    return {
      data: [
      ],
      option: {
        radius: 100, // 滚动半径，单位px
        maxFont: 20, // 最大字体大小
        color: null, // 字体颜色。为空时随机
        rotateAngleXbase: 800, // 默认旋转速度基数，数越小速度越快
        rotateAngleYbase: 800
      },
      tagList: []
    }
  },
  beforeDestroy() {
    if (this.timer) {
      clearInterval(this.timer)
      this.timer = null
    }
  },
  watch: {
    data() {
      this.$nextTick(() => {
        this._initTags()
      })
    }
  },
  mounted() {
    this._initTags()
  },
  created() {
    if (this.config != null) {
      this.option = Object.assign({}, this.option, this.config)
    }
  },
  methods: {
    _initTags() {
      this.rotateAngleX = Math.PI / this.option.rotateAngleXbase
      this.rotateAngleY = Math.PI / this.option.rotateAngleYbase

      for (var i = 0, length = this.data.length; i < length; i++) {
        // 获取球面上均匀的点的经纬度 θ = arccos( ((2*num)-1)/all - 1); Φ = θ*sqrt(all * π);
        let angleX = Math.acos((2 * (i + 1) - 1) / length - 1)
        let angleY = angleX * Math.sqrt(length * Math.PI)
        // 根据经纬度获取点的坐标，球中心的点坐标是 (0,0,0) x=r*sinθ*cosΦ   y=r*sinθ*sinΦ   z=r*cosθ;
        const x = this.option.radius * Math.sin(angleX) * Math.cos(angleY)
        const y = this.option.radius * Math.sin(angleX) * Math.sin(angleY)
        const z = this.option.radius * Math.cos(angleX)
        if (this.option.color) {
          this.$refs.tag[i].style.color = this.option.color
        } else {
          // 随机颜色
          this.$refs.tag[i].style.color =
            'rgb(' +
            Math.round(255 * Math.random()) +
            ',' +
            Math.round(255 * Math.random()) +
            ',' +
            Math.round(255 * Math.random()) +
            ')'
        }
        // 每个标签对象都有四对值
        var tag = {
          x: x,
          y: y,
          z: z,
          ele: this.$refs.tag[i]
        }
        this.tagList.push(tag)
      }
      const _self = this
      const datas = _self.tagList
      this.timer = setInterval(function() {
        for (var i = 0; i < datas.length; i++) {
          _self.rotateX(datas[i])
          _self.rotateY(datas[i])
          _self.setPosition(
            datas[i],
            _self.option.radius,
            _self.option.maxFont
          )
        }
      }, 20)
    },
    setPosition(tag, r, maxFont) {
      // 设置每个标签的坐标位置和字体大小以及透明度
      if (this.$refs.wrapper) {
        tag.ele.style.transform =
          'translate(' +
          (tag.x +
            this.$refs.wrapper.offsetWidth / 2 -
            tag.ele.offsetWidth / 2) +
          'px,' +
          (tag.y +
            this.$refs.wrapper.offsetHeight / 2 -
            tag.ele.offsetHeight / 2) +
          'px)'
        tag.ele.style.opacity = tag.z / r / 2 + 0.7
        tag.ele.style.fontSize = (tag.z / r / 2 + 0.5) * maxFont + 'px'
      }
    },
    rotateX(tag) {
      var cos = Math.cos(this.rotateAngleX)
      var sin = Math.sin(this.rotateAngleX)
      var y1 = tag.y * cos - tag.z * sin
      var z1 = tag.y * sin + tag.z * cos
      tag.y = y1
      tag.z = z1
    },
    rotateY(tag) {
      var cos = Math.cos(this.rotateAngleY)
      var sin = Math.sin(this.rotateAngleY)
      var x1 = tag.z * sin + tag.x * cos
      var z1 = tag.z * cos - tag.x * sin
      tag.x = x1
      tag.z = z1
    },
    dbclickTag() {
      if (this.timer) {
        clearInterval(this.timer)
        this.timer = null
      } else {
        const _self = this
        this.timer = setInterval(function() {
          for (var i = 0; i < _self.tagList.length; i++) {
            _self.rotateX(_self.tagList[i])
            _self.rotateY(_self.tagList[i])
            _self.setPosition(
              _self.tagList[i],
              _self.option.radius,
              _self.option.maxFont
            )
          }
        }, 20)
      }
    },
    clickTag(item) {
      this.$emit('clickTag', item)
    }
  }
}
</script>

<style scoped>
.tag-cloud {
  height: 280px;
  position: relative;
  color: #333;
  margin: 0 auto;
  text-align: center;
}

.tag-cloud a {
  position: absolute;
  top: 0px;
  left: 0px;
  color: #333;
  font-family: Arial;
  text-decoration: none;
  line-height: 18px;
  text-align: center;
  font-size: 16px;
  display: inline-block;
  border-radius: 3px;
}

.tag-cloud a:hover {
  cursor: pointer;
  border: 1px salmon solid;
}
</style>
